Finely atomized aerosols have found use in a number of applications in recent decades. For instance, respiratory ailments such as COPD, cystic fibrosis and asthma are often treated by inhaled aerosol therapy. Some advantages of inhaled aerosol therapy include the ability to effectively deliver a therapeutic agent directly to the site of need (e.g. the lungs) without high systemic exposure. Accordingly, devices for use in aerosol therapy (e.g. metered dose inhalers, or MDIs, dry powder inhalers, or DPIs, and nebulizers) have been used for the treatment of respiratory disease.
Ultrasonic mesh nebulizers operate by producing high-frequency ultrasonic waves, which create tiny, inhalable droplets from a liquid (e.g. a solution containing a therapeutic agent). The size of the droplets is important; ideally droplets range in size from 1-5 μm. Droplets that are too large (e.g. >5 μm in diameter) tend to be absorbed in the throat and mouth before reaching the lungs. Alternatively, droplets that are too small (e.g. <1 μm in diameter) tend to be exhaled without being absorbed in the lungs. Because the size of the aerosol droplets produced is dependent upon the diameter of holes in the mesh used in the ultrasonic mesh nebulizer, it is crucial that ultrasonic mesh nebulizers use a mesh in which the holes are of uniform and appropriate size (e.g. preferably less than 4 μm in diameter).
In some instances, ultrasonic mesh nebulizers have been used for the delivery of drugs to the lungs of infants in the context of neonatal care. In such cases, it is advantageous for the aerosolized particles to have uniform characteristics and to be of the appropriate size (e.g. preferably less than 4 μm in diameter).
Current manufacturing processes used to make porous mesh plates may use focused lasers, ions, or electron beams, or use lithography techniques to directly generate holes, or pores, of the desired size in a given substrate (e.g. a plate). These techniques can be costly because they often require the use of specialized drilling equipment and thin, delicate films in which the holes are drilled to form a mesh.